Brake-applying apparatus



I Ma 1 y 927 s. w. DUDLEY ET AL BRAKE APPLYING APPARATUS v Filed May.11."1925 trains, makes very Patented May 10, 19.27.

tiarrsosrarss/ SAMUEL w. DUDLEY, or NEW HAVEN, 'eoNNne'rIeUT, AND CHARLES s- BUSHNELL,

or noonnsrna, NEW YOBK,.ASSIGNORS EEO-GENERAL RAILWAY SIGNAL COMPANY,

or ROCHESTER, NEW Y R'K.

reassu- Marat caries.

BRAKE-APPLYING APPARATUS.

Application fi lediMay 11,

This invention relates to braking systems for. railway trains, and more particularly to manually operable brake applying apparatus which may be automatically operated and if so operated etlects two-stage brake application.

in applying automatic train control torailway systems andin order not to bring an additional hazard upon the train as a-result ot a brake application effectiveautomatically, as is the case it an'autoinatic brake application is. efiiected-too quickly, which nay re sult in a wreck by reasonof buckling of the train, or the like, mechanism for eitecting a less severe brake applicationis desirable. The engineer when applying the brakes manually, especially on long freight light brake application totalze up the slack'between cars after whichhe follows this up with a heavy brake application intended to bring the train to a stop quickly. In providing automatic'apparatus for applying the brakes it is: desired to have this apparatus simulate a inanual' application as near as ispracticable with such automatic apparatus.

fln accordance with the presentinvention it is proposed to provide means whereby the automatic apparatus, which is to be applied to a braking system of the type in which the brake pipe is normally charged and in which the venting of the brake pipe etlects a brake application, is constructed so that a light or prelin'iinary reduction in equalizing reser voir pressure of seven or eight pounds is "irst made and in which after the expiraion of a time interval, a further reduction eiiected, so that, the total reduction is that necessar to effect a full service brake application. In constructingmechanism of this kind it is rather difficult to determine the period of time which should elapse between the firstand secondreduction, especially bearing. in mind that the equivalent is at times to be used for short or light v-ains and at other times for long or loaded trainsz' also, under some conditions it will be desirable to even start the second venting 1925. Serial N 29,430.

the equalizing reservoir pressure due to the rst reduction in equalizing reservoir pressure, and still obtain a brake application difierent from that or a single stage or fullservice brake application. This ditlerence between an overlapped two-stage brake applicationand a single stage brake application of the same ultimate brake applying pressure reduction is believed to be due to the taetthat the equalizing discharge pis-' ton valve contained in the usual H estinghouse engineersbrake valve (which maybe assumed to be the one employed in apply' ,ing the present inventlon) efiects a tapering discharge of fluid pressure'trom the brake pipe upon a reduction in equalizing reservoir pressure, that is, thise-qualizing discharge piston valve does not open up' widely and stay opennntil brake pipe pres sure has dropped to equalizing reservoir pressure but opens widely and gradually closes up so that the discharge of fluid pres sure from the brake pipe is not dependent on pressure alone but is dependent on the pressure existing in the brake pipe and'the position oi this equalizing discharge piston valve. i1 Q More specifically, it is proposed in accordance with the present invention to provide two reduction reservoirs into which (he equalizing reservoir may discharge upon an automatic application of the brakes ettected by operating the engineers brake valve itself, timing means being provided which maintains these 'two reduc ion reservoirs isolated until an interval of time after the automatic brake application is begun, this timing means being controlled directly by an eloctro-pneumatic "valve which also controls the automatically operated engiill erence will be made to the accompanying drawings, in which l igr. 1 shows brake applying apparatus embodying the present invention tor etl'ectiugr a two-stagc brake application in which suitable timing means in initiated directly by an electin-pneumatic valve which controls the brake applying apparatus. and in which the time between the two stages may be shortened by the pneumatic valve which controls the brain applying apparatus and in which the time between the two stages may be shortened by the engineer at wil and Fig, 2 shows a modified arrangement oi" the system shown in l l r. 1 in which the enniacin: cannot intertere with the time intervening hot-ween the two starter;

The automatic brake valve AllV #hown conventionally coniprisrea the main casing: l of the usual. engineer-a bralze valve, which may be annulled to he the well known lleat ing'housie ll engineefln brake valve, and which contains the uaual equalizing dis charge piston valve L, which valve cancer; brake pipe pressure to be discharged from the brake pipe ll]? through the valve port of valve "2 and the service exhaust fitting; 3 when the pressure in the brake pipe ill in higher than tha' in the equalizing reservoir 1* This enfzineers brake valve has its usual cap removed therefrom and is provided with a special cap ilupon which is caper-imposed a brake *alve actuator including; a small cvlinder 5 normally connected to main reservoir prtaezure supplied through the el ectropneu-- niatic valve EPV from the main reservoir MR. lhis large cylinder is vented to atmosphere through the exhauat port EX ot the device lfill l when this: device in in its le-enert iztal position, The cylinders and (3 contain platoon eonnecttal together by a rack which raclt in adapted to operate the rotary valve in the engrineers hralle valve when pressure is vented from the large evlinder (3, this mechanism being so eonatrueted that the engineers brake valve han dle T diaconncded lrom the rotarv valve iitnelit when the valve is automatically op crateth no that the engineer cannot Ulllltlr t operation oi the valve or annul each opera tion by re-charc'inp; the braae pipe alter the bralze val 'e is operated. This automatic brake valve r tlll also includec a supplemental rotarv valve (not specifically shown). which is contained under the cap 8 and mechanically connectml to the main rotar v valve in the engineers brake valve so as to move with it. This supplemental valve eonnectcal to the equalizing; reservoir E through the pipe 10 and ports and cavities therein for connecting this equalizing reservo r E to the reduction reservoir R when the engineers brake valve is in the service or energizing position, and for isolating this equalizing reservoir E from the reduction reservoir R and connecting the re duction reservoir illto atmosphere when the valve ABV is in the lap, holding, run ning, or release position. In this connection it is desired to be pointed out: that the usual engineers brake valve itself has been nlightl v modified to adapt it to the present invention by having its service exhaustport, which port is contained in theseat of the uaual rotary valve and which leads to the equalizing reservoir, plugged upso that the equalizing reservoir not vented to illZITflOS' phere when the engineefis brake valve in in the FJGL'VlLG position; that; is, the equalizing; IPHHVUil" .ll can only discharge through the aup neinental valve containedunder the cap ll when the engineer-n bralte. valve is in the service position and then can not. be vented to atmosphere directly butcanonly vent to the reduction reservoir R. For a further and more detailed description of this auto- :atie engineerrs brake valve ABV, attention is directed to the prior appli -ation o l Charles li'i. Bushnell, tilerial No. 16,937, tiled March 90, 1925.

In order to at times connect the reduction reaervoirs ll and R togetl'ier and at; other times isolate them from each other and vent the reduction reservoir 1i to atmosphereyan electrically operated valve EV is QIDPlOYtiCl.

This electrically operated valve includes a valve stem having tappet valves 16 and 1"? connected thereto, which valves 16 and 137 are adapted to rest against their respective seats when the winding; 18 of the valve EV is energized and tie-energized respectively. It will he noted that; the reservoirs R and It are isolated from each other when the valve 1W is energized and that; the reduction reaervoir R connected to atmosphere tin-(nigh the port 19 under this condition, and that the two renervoirn il and ll are connected together when the valve, l lV in de-encrgizml, the sprin :20 being; eniphnnal to move the stem 15 ulnvardlv upon le-enorgrization ot the winding Ill,

The present invention employs a timing device '1. which device derives its; operating energy from main l'th't'll'l'Oll. pressure existing in the reservoir MR, not specifically shown. This timing: device '1. is constructed so that the contac. 21 forming part thereot open substantially a definite period of time atter the timing device '1 in initiated irres 'iective ol? variation in main reservoir n'esaurc. This timing or time element device T comprises a small chamber normally connected by the pipe 2 3 to main reservoir pressure ha ring a diaphragm constituting one wall thereof, and a large chamber 25 including a large diaphragnn 26 which large chamber in connected to the timing reservoir Tll, by the pipe 27. The timing reaervoir Tl-l under normal energized condition of the device till ion

llifi EPV, is connected to main reservoir pressure through the pipe 28, restrictedpassage. or orifice 29, pipes 30 and 31 through the device EPV and pipe 32. It now, the device EPV is ole-energized the large cylinder 6 of the brake valve actuator and the timing reservoir TR are connected to atmosphere through the exhaust port EX ot'the device EPV, the largecylinder 6 is immediately vented and the timing reservoir TB is gradually vented throughthe-restricted orifice 29, so that contacts'2l are Opened when the pressure in the timing reservoir TR has fallen'to a value so that the force exerted on the large diaphragm 26 no longer exceeds that of the force exertedupon the small dia valve and the supplemental valve assume the running position; further the electrically operated valve EV is also energized through a tircuit readily traced in the drawings which includes the contact 35 contained in practice in the actuator casing of the'device ABV. This contact 35 is only open during the lap and service'position of the engineers brake valve handle 7 and is'not opened it the rotary valve is operated automatically by thebrake. valve actuator. a

ilz anual operation (Fig. 1) .Let us' as sume that the engineer wishes to apply the brakes manually with the brake applying apparatus shown in Fig; 1,.and in order to do so moves the brakevalve handle 7 to the service position and leaves it there until equalizing reservoir pressure has been reduced sayfrom 8 to 10 pounds, which is considered a sufficient reduction to bunch the slack between cars and that he thereafter returns the handle 7 to the lap position.

During all this time that the handle 7 was in the service and so long as it is not're'turned beyond the lap posit-ion the contact 35 is separated from the stationary contact illustrated by'an arrow and the device EV is de-energized. Also, With the handle 7 returned to the lap position the reservoirs R and R are permitted to vent to atmosphere through the supplemental valve for reasons heretofore given. This of course effects a reduction in brake pipe pressure for reasons heretofore given and results in a light brake application. Let us further assume that the engineer is now ready to make a further re duction to complete the necessary reduction to make a full servlce'brake application and that he moves the handle 7 to the service position and leaves it there until a full service reduction, of say twenty pounds, from the original pressure,'has been made, after which he returns the handle to the lap position. a. p

With this further reduction in equalizing reservoir pressure the equalizing discharge piston valve 2 vents the'brake pipe until its pressure has fallen to the pressure existing in the equalizing, reservoir E. The net re sult i 's, that amannal application made by the apparatus shown is substantially. the

same as thatof the usual air brakesystem only thatthe equalizing reservoir isvented into the reduction reservoirs R and R-instead of being vented directly to atmosphere. In this connection, it should be noted that if the engineer wishes to make a full service brake application in one stage he maymove his brake valve handle 7 to the service position and leave it there, and in so doing he Will-efiect a full service brake application without waste of air because the volume of the reservoirs R and R is such that if equalizing reservoir is vented to these two reduction reservoirs the equalizedpressureis that necessary to 'efi'ect a full service brake application. Further, it should be noted that the timing device T need not be consid ered during a manual application because the circuit controlled by this timing device T is open so long as a manual application is initiated and maintained.

Automatic operation (Fig. 1). Let us now assume that'an automatic brake appli cation is to be imposed possibly because the train is entering a caution block, is approaching a drawbridge or other hazardous territory, or that an automatic brake appli cation is desired because the engineer isnot vigilant and is not attending to his duties, or at leastlhas not" manifested FUCll vigilance and that for any one of these reasons the device -EPV is de-energized by suitable train control mechanism.

position also, vents the timing reservoir TR but by reason of the restricted orifice 29, the timing reservoir TB is very gradually ventcdi and only opens contacts 21 after the expiration of a'period of time. Movement of the supplei'ncntal valve and the rotaryin. the cnginecrs ln'altc valve to the FKIBITIK'Q position iaulsea the equaliziijitr rchervoir i to he connected to the first reduction reservoir B through aport oi the proper aizc to cil'cct the pri'ipcr gradual reduction in the equalizing: rcs; ."oir 1*). The "atio of volumes oi? the ItlhtlVOll't id and ll in fl-llit'll that it the reservoir it, which is normally connected to atnlosphcre, is allowed to ctpialmc with the pre aim in the rescrroir 1*) that a reduction oi seven or eight pounds in tantalizing H rvoir ]'Jl'tf-'.- lll( takes: place, which is considcred to he the propcr rudiu-iiou tor ellcctingr the tirat stage application in a two-stage hraltc application. li'ith i'hh: rcductionin equalizing rc.- crroir prcsnurc the lJtllCO pipe is vented through the usual equalizing); discharge piston ralrc until hraltc pipe PTOSSUIO has alm fallen to the name ciitcnt.

At about this time. or powa'ihly a little earlier or a little later, the contacts 521 oi the timingdcvicc 'l are opcned. This opening oi contacts 21 hrcalo tho merit ling; circuit for tho clcctrically operated valve EV, ro that thin valve quickly 21love: to raised or de-cncrg iiicd position thereby cuicltly connecting the rcduction rcrecrvoiru R and It to iicthcr without the cacape olf air to atmosphcre at'tcr which a new equalization cl prcsiaircn ta ltcu place hctwccn the reservoirs E, It and R the volume of the reduction reacrvoirs it hcin r such that the new equalizcd prcesure hetwcen these three reeeiwoiru is such as to cilect a "full ervi :c hrahe application. With tho cqual' iingr reservoir E reduced to this: new prcsaurc value the hralte pipe is again vcntcd through the medium ol" the cqualiz iing discharge piston valve 2, no that the second shine oi the hralte application is consunimated.

The appa atus shown in liinj. 1., thus provideo means whcrchy the oinrinccr may malte a tall H'l'YlCO hra :e appli altion without the aisle oi? air, h v merely moving the hralte valve to the :scrvicc position, and, which al.- lows him to make a n1ulti-atagre hralto appli cation lrv operating; the handle T in the usual manner and which also permits him to shorten the time intervening between the two stages oi an automatic hr-al c application. lrv merely moving his handle to tho lap position and in so doing retract contact 255 and eti'ccti derncrgination of the clectnicall ope atcd valve EV whcrchy the two reduc tion reacrvoira are connccted together.

i tructurc (Ft/ l3).lfn the arrangement shown in Fin. it the electrically operated valve EV, ;hc device EPV, the time clelncnt divice 'l, the reecrvoirs B, it" and R and the timing reservoir TR are the same as shown in the braking system illustrated in Fig. l and therefore need not; he described. The automaticallyoperable engineei."s brake valve ARV is the same as that shown in Fig. 1 except that it. doceinol; include the con tact 35 ope 'atccl by the enginecrshrake valve handle 7, the modified construction shown in Fig. having been providedfto avoid any electrical wiring or presence of contacts and the liltc in connection with the engineers hr-mc valve.

time in the arrangement shown in Fig. 2, manual operation of the engineefis brake valve ran not e'tl'ect de-energization of the electrically operated valve EV by reason of the omission oi contact 35, thevalve EV is preferably normally de-cnergi izcd, so that manual operation of the engineers lJItiltQ/ valve to thc norvicc poaition elt'ccts a full service brake application because the reservoirs R'- and it" arc normally connected together. In ordt-ir, litnvcvcr, iohavc renew voirs R and It" iaolatcd From cach othcr an soon as; an automaticbrake application is initiated. a pneumatically operated circuit controller Pt) is employed which closes the circuit for energiZingthe valve EV at one point immediately upon deciiernization oi the dericc lulV and. before the hraltc valve actuator has actually lllOVOtl the brake valve to tho service position. This pneumatica lly operatcd circuit controller PU c011- of a cylinder all haviin a piston +11 thcrein connected to a stem l2 carryingan insulated contact fl-ii, which piston is normally held in the position shown by main reservoir prceuurc existing in cylindcr +10 against the opposition oi? the compression spring let. Obviously thc release of pressure from cylinder =10 causes the spring etil to operate the pi ston ll and close the contact; til.

ilfmium operation (1 .Z).The manual operation of the apparatue shown in Fig. L- is the saint: as that ol? the a iparutus S'llUWll in Fig". ii an far as functions are conceri'ied. it should, however, he noted that; in the arrangement shown in ljig. 9 the clcctrioally operated valve EV is normally tic-energized and. continues to remain (lO'tlK l'glZO/Ll upon the manual. application; whcrcau in the arranggcincnt nhown in Fig. l the clcctrically operated valve lll i:- normally cncrgized but; in llt!tlltl. lZ(tl as soon 11H the cngineer a hralte valre is moved to the [up or service position manually, alao that both of these arrangrcmcnts permit tho engineer to make a manual I) aim appli 'ation in substantially the same way.

Alarm/202 2 0 operation (F /'1]. f3).--Let US as- 55111110 that the device lQPV is tie-energized by suitahle train control nicchanism for any ouc of the various reauonu hcretoiore mentioned. lle-eneigization oi. the device ElV diaconnccts main reservoir pressure from the large cylinder (5, the timing;- reservoir TR and the cylinder {t0 of tho pncun'iatic circuit cont-roller P l and einiultaneously with such removal oi main reservoir pressure the cylinders 6 and ll) and the timing reservoir TR lit) are connected to atmosphere. These various devices @116 so constructed that the circuit controller PC isfirst closed immediately after which the engineers brake valve assumes the service position by reason of operation sonsheretofore given thus effecting a light brake application sufficient to bunch the slack "between cars and placing the train in a condition to receive a full service brake application. By reason of the restricted orifice 29 a definite period of time must elapse before contacts 21are opened. hen this time has elapsed, contacts 21 open and the device EV is again de-energized thereby connecting the reduction reservoirs B and R together. With'the equalizingreservoirs E new con nected to both the reduction reservoirs it? and R a new equalization of pressures results, which by reason of the volumes of the reservoir selected is such as to give a full servicebrake application.

It should be noted that the automatic operation of the system shown in Fig. 2 is the same as that shown in Fig. 1 except that initiation of an automatic operation in Fig. 2 energizes the electrically operated valve EV, whereas this valve is already energized in the system shown in Fig. 1. Further, it

should be noted, that the engineer can not intervene as to the amount of time required before the second stage of brakeapplication takes place automatically. in the, arrangement shown in Fig. 2 as is possible in the arrangement shown in Fig. 1. 'This, however, does not materiallyinterfere with .the

engineers free manipulation of the brakes when an automatic brake application has been started, because the time delay, effected by the time element'device T is very short,

' and further, if desired the engineer may make an emergency application if he finds this necessary.

Having thus shown and described several embodiments of a brake applying system which may be either operated manually or automatically and which. if operated automatically effects a two-stage brake application with a limited reduction in brake pipe pressure and in which the engineer at all times is free to do what is necessary towards stopping a train, but in which he is not free to release the brakesunt-il'such release of the brakes is made possible by suitable autonot been specifically shown; it is desired to be'understood thatthe specific apparatus shown has not been illustrated for the pure pose of showing the scope of the'invent'ion .r tiie exact construction preferably emmodifications and additions may be made to apply the brake'eontrol mechanism to the particular type of braking system in connection with which ll} ISiIO be used, without departing from the-scope of the invention or the'idea of means underlying the same.

. What'is desired to be securedbyLet-ters Patentis: I

1. Brake applying apparatus for trains alo' ed in practice and that various chan es 1 employing a braking system of the type in I V which the brake pipe is normally charged and in which venting thereof effects a brake application; the combination of an equalizing reservoir, a brake pipe, an equalizing discharge piston'valve connecting said equalizing reservoir and brake pipe for exhausting air from the brake pipe to atmosphere if brake pipe pressure is higher than equalize ing reservoir pressure, and two-reduction reservoirs normally connected together; a

brake applying valve which maybe controlled manually; automatically controlled pneumatic means for operating said valve to the brake applying position, saidvalve if operated to the brake applying posit-ion connectingsaid equalizing reservoir to one of the reduction reservoirs, thereby effecting a predetermined "reduction in equalizing reservoir pressure; pneumatically controlled means connected to be operated when said first mentionedpneumatic means is operated for isolating said two reservoirs from each other;'and means annulling the effect of said last mentioned means effective a predetermined time afterlsaid' automatically controlled pneumatic means is operated, whereby said two reservoirs are again connected together and a second stage'of reduction of equalizing reservoir pressure results.

2. Brake applying apparatus. for trains employing a braking system of the type in which the brake pipe is normally charged and in which venting thereof effects a brake appli ation; the combination of a main reservoir, an equalizing reservoir, and a first and a, second reduction reservoir; an equalizing discharge piston valve connected bellU tween the'brake' pipe and the equalizing.

reservoir which discharges air from the brake pipe whenever brake pipe pressure is higher'than equalizing reservoir pressure;

an engineers valve which if operated to the serv ce position vents 531d. equalizing reservoir into'the first reduction reservoir; an

actuator for operating said valve tending to connected to a source of. air pressure, which.

. cjylinder acts" tofcausei said actuator to asill voir.

sumo a normal position in which the engineers hrzlte valve not operated; means tending: to assume a position to ellect isolation ottho first and second reduction reservoirs and including; a cylinder normally connected to a source of pressure causing it to assume a position connecting said reservoirs; automatic means for simultaneously controlling said actuator and said first mentioned nieang by venting: both of said cylinders wherein the tutored ction reservoirs are inolated from each other and said equalizing reservoir is connected to the first reduction reservoir; said first mentioned means being cilective to isolate said two reduction reser voirs t'roni each other For a predetermined interval of time only.

i}. .llralte applviug apparatus for trains employingui braking system of the type in which the hralte pipe is normally charged and in which ventingthereot ellects a brake .application; the combination oi. a main rei-=- ervoir an equalizing reservoir, and a that undo second reduction reservoir; an equalizing discharge piston valveconnected between the brake pipe and the equalizing reservoir which discharges air troin the brake pipe whenever brake pipe pressure is higher than. equalizing reservoir pressure; an engineer-l; brake uilve which it operated to the service position vents said equalizing reservoir into the first reduction reservoir; an actuator forpperating said *alve tending to cause said valve to assume a, brake applying position including a cylinder normallv connected to a source of pressure so that the piston in said cylindercauses said automatic means to assume a normal. position in which the engineeirs brake valve is not, operated; means tending to assume a position to eilect isolation of the first and the second reduction reservoirs including a cylinder normally connected to a source of pressure causing it to assume a position con- .necting said reservoirs; automatic means for simultaneously controlling said actuator and said nieai'is hy venting fiflltl cylinders, whereby the two reduction reservoirs are isolated from each other and said equalizing; reservoir is connected to the first reduction res ervoir; said first mentioned means including a time element device comprising, ditterential piston mechanism operated by air pressure derived from said main reservoir and c tlectim to again. connect said two reservoirs together a liter a u'cdeterinined interval of" time i rrespc -tive of slight variations in main reservoir pressure.

.11. Brake applying apparatus for trains mnplovinga braking s steni of the type in which the brake pipe is normally charged andin which venting; thereof effects a brake tion 3 the combination ofa znain reseran equalizing reservoir anda first and a second reduction reservoir; an equalizing discharge piston valve connected between the brake pipe and the equalizing reservoir which discharges air troni the brake pipe whenever hralre pi pe pressure is higher than equalizing reservoir pressure; an engineers brake valve which it operated to the service position vents said equalizing reservoir into the first reduction reservoir; an actuator for operating aid valve teni'lingg to cause said valve to assume a brain applying position llltldtlil'lg a cylinder norn'iallv connected to a eource of pressure thereby causing said automatic means; to asauine the normal. position. in which the eirs 'ineers hralte valve is not. (nierated; means tending: to assume a position to elicit isolation of the first and second rcwluction reaervoirs ii'icluding :1 cylinder normally connectedto a source oi. pre: sure causing it to asuunzea position connecting said reservoirs; automatic meanstor sinulltaiuouslv controlling; said actuator and said means hv venting said ovlinders whereby the two red. ction reservoirs are isolated from each other and said equalizing reser veir is connected to the first reduction reser voir; said tirstn'ientioned means including a time element device comprising" a large and a small surface against which inain reeervoir pressure acts and from which pressure is vented from the large surface upon actuation of said automatic means which is c'tlective to again connect said two reservoirs together when the total pressure against each till oi: these surfaces is the same wherein; the

time during which the two reduction rcservoirs are isolated is substantially the same irrespective oi. slight changes in main reservoir pressure.

5. Brake applying apparatus for trains emploviin, a braking svatein oi? the type in which the hralte pipe normally charged and in which venting thereof effects a brake application; the combination of a main reservoir, an equalizing reservoir, and a first and a second. reduction rest-irvoiran equalizing: discharge piston valve connected be tween the brake pipe and the equalizin rvreservoir which discharges air from the hralie pipe whenever bralte pipe pressure is higher than equalizing reservoir pressure; an enuiwrcers hralie 'alve which it operated to the service position vents said equalizing reservoir :into the tirat reduction rer-rervoir;

llii

an actuator for operating mid valve tend ingto cause said valve to nne a hralic applying position including); a cylinder nornially connected to a source of pressure whereh the piston in said cylinder cans-rs till) said automatic means to assume a normal. po-

sition in which the (BDQ'lHGEEL' S hralte valve is not operated; mechanism for isolating the first reduction reservoir from the second reduction reservoir when operated; a. tiineeleinent device for connecting thefirst reduetion reservoir to the second reduction reservoir a predetermined period of time after "it is initlated; and automatic means for simultaneously actuating said actuator, said -mechanism and said time element device;

ated means for opening said contacts when the pressure in said reservoir has dropped a predetermined per cent below its original nine, and means for effecting such reduc tion including a restricted opening and means for venting said timing reservoir through said restricted opening, whereby the time required to open said contacts is suh stantially the same regardless of the orig" inal pressure existing in said timing reservoir. s r v r 7. Brake control apparatusfor automatic train control systems of the type in which the brake pipe is normally charged and in which a reduction in brake pipe pressure effects a brake application, the combination with an equalizing reservoir, a brake pipe, an equalizing discharge piston valve for discharging pressure fluid from the brake pipe so long as brake pipe pressure is higher than equalizing reservoir pressure, two reduction reservoirs to one of which the equalizing reservoir is connected when an automatic brake application is to be effected, and means-operated upon an automatic brake application for isolating said reduction reservoirs from each other for a period of time S. A pneumatically operated time element device for automatic train control systems comprising, a pair of contacts, a timing reservoir, a main reservoir, differential pneumatically operated means for operating said contacts including two opposing members one of which is of large area having the fluid pressure in said timing reservoir act ing thereon and the other of which is of smallarea' having main reservoir pressure acting thereon, means for 'norn1ally charging said timing reservoirto thesame pressure as that existing in said main reservoir,-

and means for venting said timing reservoir through a restricted orifice and I operated when'the time period is to be started, whereby said contacts'are operated substantially a fixed interval of time after said venting is started regardless of the pressure existing in said main reservoir.

9. A pneumatically operated time element device for automatic train control systems comprising, a pair of contacts, a timing re el'voir, a; main reservoir, differential pneumatically, operated means for operating said contacts including two opposing diaphragms' of which one is of large area having thefiuid pressure in said timing reservoir acting thereon and of which the other is of small areahaving main reservoir fluid acting thereon, said timing reservoir to the same pressure as that existing in said main reservoir, and means for venting said timing reservoir through a restricted orifice opened when the time period is to be started whereby said contacts are operated substantially a fixed time interval after said venting is started regardless ofslight variations in the pressure existing in said main reservoir.

pressure means normally charging 10. Brake applying apparatus for air brake systems of the type in which thebrake pipe is normally charged and in which vent- I ing of the brake pipe effects a brake appli cation, an automatic brake applying de ice maintained in its normal inactive condition by'fluid pressure contained in a pipe which if rendered active effects a predetermined reduction in brake pipe pressure, an electrically opera-ted valvefor normally con 'necting saidpipe to a source of fluid pressure and for venting fiuidpressure from said pipe to atmosphere under adverse trafiicconditions ahead, and supplemental brake applying means including a timing'reservoir connected to said pipe through a restricted opening which effects further venting ofthe brake pipe a predetermined interval of time after said brake applying device is rendered active. 7

11. Brake applying apparatus for air Edi) brake systems of the type in which the brake pipe is normally charged and in which venting of the brake pipe effects a brake application, an automatic brake applying device maintained in its normal inactive condition by fluid pressure contained in a pipe, an electrically operated valve for normally connecting said pipe to a source of fluid pres sure and for venting fluid pressure from said pipe to atmosphere under adverse trafiic conditions ahead, and timing means including a ring reservoir connected to 7 said pipe through a restricted opening.

12. Brake applying apparatus for air brake systems of the type in which the brake pipe is normally charged and in which venting of the brake pipe effects a brake application; and an automatic brake applying device maintained in its normal inactive condition by fluid pressure contained in a pipe which if rendered active effects a predetermined reduction in brake pipe pressure; anelectrically operated valve for normally connecting said pipe to a source of fluid pressure and for venting fluid pressure from said pipe to atmosphereunder adverse traflic conditions including; a supplemental brake applying means including :1 timing reservoir connected to said pipe through a restricted opening; apnennmtically operated Contact mechanism connected to said pipe and ren- (lei-ed active Whensnid pipe is vented; and

sn )p1ementn1 brake applying means rendered znwtwe when szud automntlc brake npplymg device is operated, said Contact lnechanisn'l is o mz'ni'ed and said timing reservoir has been "vented to a predetermined extent.

In testimony whereof We affix 0111' signetures.

SAMUEL V; DUDLEY. CHARLES S. BUSHNELL. 

